Pathological characteristics predicting sentinel lymph node metastasis in early breast cancer patients.

Background: In this study, we aimed to identify the predicting pathological factors affecting sentinel lymph node biopsy (SLNB) in patients with clinically node-negative breast cancer.

Methods: Our single institution retrospective study was conducted at the Cancer Research Center of Shahid Beheshti University of Medical Sciences from 2018 to 2021. Data were imported into and analyzed using SPSS Version 28 for Windows (IBM Corp., Armonk, NY, USA).

Results: Of the 76 patients who underwent SLNB, 43 (56.6%) had negative SLNB and 33 (43.4%) had positive SLNB which led to axillary lymph node dissection (ALND). The relationship between hormone receptor status (ER/PR/Her2), pathology type (IDC, ILC, DCIS, LCIS), tumor size, and Ki67 expression was assessed. According to the results, axillary lymph node involvement can be predicted based on the scores and results of the three variables: IDC tumor type, lympho vascular invasion (LVI), and Ki67 expression. The positive relationship between IDC tumor type and LVI with SLNB indicates that with positive IDC tumor type and LVI, there is a higher probability of positive axillary lymph nodes (3.88 times higher probability for IDC tumor type and 6.75 times higher probability for the LVI factor). However, when the Ki67 expression is lower, the probability of positive axillary lymph nodes is higher (3.58 times higher probability).

Conclusion: IDC tumor type, LVI, and lower Ki67 expression are independent predictive factors of positive SLNB.